BENDIX SD-15-4106 manual Removal, Caterpillar output voltage is Pulse Width Modulated

Closed Throttle (open) Range: 10-20%

Open Throttle (full) Range: 75-90%

	PIN A VREF
	(INPUT)
	-8V
	2000 OHM ±5%
	RESISTOR
PEDAL	PIN B
POSITION
SENSOR	VOUT
(PWM)	(OUTPUT)
	RED	(CABLE)
.001µF	47,000 OHM ±5%
	RESISTOR	POTENTIOMETER
	PIN C	VOLTMETER (V => %)
	GROUND
	BLACK

Caterpillar output voltage is Pulse Width Modulated

FIGURE 8 - ET-S™TREADLE ELECTRICAL TEST SCHEMATIC FOR THE CATERPILLAR CONNECTOR

potentiometer until the ohmmeter reads the same resistance as shown on the label within ±10 Ohms. Next, while holding the potentiometer at the set resistance screw and lock the potentiometer in place (torque to 25 inch pounds ±5). The sleeves lock into the body of the potentiometer for easy removal and reassembly.

Test 2: Where the potentiometer has no label, but

has engraved set voltage shown. The Cummins potentiometer on the ET-2™treadle has an integral idle validation switch. It also has a set voltage value marked on the cover, which needs to be used to properly install the potentiometer. The drive slot in the potentiometer should engage with the drive tang at the end of the drive shaft. Next rotate the potentiometer until the hole in the metal sleeve matches the mounting holes on the actuator base. Loosely screw the potentiometer in place but do not tighten. Construct the test circuit following the circuit diagram shown in Figure 8. To make the test circuit connect the test load resistor (47,000 Ohms) and a capacitor (.01 Microfarads) across pins 3 and 4 of the potentiometer. Then connect a voltmeter to the lead ends of the test circuit. Next connect a 5 volt power supply to the potentiometer at pin 4 (APS ground) and pin 5 (supply voltage). Caution: Sensor may be damaged if supply exceeds 5 volts. Now the installer should read the set voltage value marked on the potentiometer. Rotate the potentiometer until the voltmeter reads the same voltage as shown on the potentiometer within ±.02 volts. Next

screw and lock the potentiometer in place (torque to 25 inch pounds ±5). The sleeves lock into the body of the potentiometer for easy removal and reassembly.

Test 4: For CAT engines:

1.Securely clamp the treadle Mounting Plate (6).

2.For Caterpillar Potentiometers: Aligning the drive slot, the Potentiometer (1) engages the drive tang at the end of the Cam Follower Drive Shaft (see Figure 4). Rotate the Potentiometer clockwise until the first set of mounting holes align. Secure using two screws (2): torque to 20 (±2) in. lbs.

To test the Caterpillar sensor construct the test circuit shown in Figure 7. Connect both pin B and pin C into a voltmeter. Set the voltmeter to the settings described in Figure 7. Record the output values in Figure 2. If the unit does not operate within the specified ranges, service the unit or replace it with a new ET-2™treadle.

REMOVAL

1.Park the vehicle on a level surface and block the wheels and/or hold the vehicle by means other than the air brakes.

2.Drain the air pressure from all vehicle reservoirs.

3.Unplug the cable assembly at the opposite end of the potentiometer. Disconnect by lifting the lock tab and pulling the connectors until they disengage.

4.Remove the ET-2™treadle from the vehicle.

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